Letters to the Editor
nators appears at ﬁrst to be arbitrary foration or penetration of the visceral 1. Washington MK, Berlin J, Branton PA, et al.
Protocol for the examination of specimens from
and to ﬂy in the face of the literature peritoneum) has a 10% to 20% better patients with primary carcinomas of the colon
that you cited. However, when the 5-year survival than locally invasive and rectum. Arch Pathol Lab Med. 2008;132:
predecessor to the current Hindgut carcinomas for each category of N.6 1182–1193.
Although the incidence of R0 resec- 2. Greene FL, Page DL, Fleming ID, et al. Co-
Task Force of the American Joint lon and rectum. In: Greene FL, Page DL, Fleming
Committee on Cancer met to propose tions is not clear in the SEER analy- ID, et al, eds. AJCC Cancer Staging Manual. 6th
changes for the TNM staging system sis, the cooperative group data in- ed. New York, NY: Springer; 2002:113–124.
clude only R0 resections and have the 3. Compton C, Fenoglio-Preiser CM, Petti-
in the 6th edition of the Cancer Stag- grew N, Fielding LP. American Joint Committee
ing Manual, its review of the literature same pattern in rectal carcinoma. In on Cancer Prognostic Factors Consensus Confer-
suggested that there was insufﬁcient addition to these data that are pub- ence: Colorectal Working Group. Cancer. 2000;
outcome data to recommend the licly available, there is a third data set 88:1739–1757.
4. Zeng Z, Cohen AM, Hajdu S, Sternberg SS,
adoption of subsets for T4. In the 6th from the National Cancer Data Base Sigurdson ER, Enker W. Serosal cytologic study
edition of the manual,2 subsets were that also conﬁrms that the new T4a to determine free mesothelial penetration of in-
not recommended for T4 but it was has a better outcome than the new traperitoneal colon cancer. Cancer. 1992;70(4):
clearly understood that more data ¨ ¨
5. Vogel P, Ruschoff J, Kummel S, et al. Prog-
should be collected for the 7th edi- A meeting was held with the In- nostic value of microscopic peritoneal dissemi-
tion to determine whether such sub- ternational Union Against Cancer nation: comparison between colon and gastric
(UICC) last spring to harmonize this cancer. Dis Colon Rectum. 2000;43(1):92–100.
sets should be adopted in the future. 6. Gunderson LL, Jessup JM, Sargent DJ, et al.
The biologic rationale that you sug- change and other proposed changes TN categorization for rectal and colon cancers
gest and that was clearly articulated to the TNM staging system for the based on national survival outcome data [ab-
at the 2000 CAP Prognostic Factors 7th edition of the manual. The UICC stract]. J Clin Oncol. 2008;26(suppl 20):4020.
Conference3 seemed compelling. Cer- has agreed that the T4a and T4b sub- The authors have no relevant ﬁnancial
tainly, one would think that free per- sets should be free peritoneal perfo- interest in the products or companies de-
foration into the visceral peritoneum ration or visceral penetration for T4a scribed in this article.
and invasion into an adjacent organ
(the original T4b) would have a
or structure for T4b.
worse outcome with greater local re-
This process demonstrates how
currence than a locally invasive can- important it is to formulate postu-
cer that was ‘‘covered’’ early on as lates and then assess them in data
you elegantly describe (the original sets that are larger than single insti- Melamine-Containing
T4a). Early data by Cohen and col-
leagues4 suggested that the incidence
tutional series. As we go forward Crystals in the Urinary
with this checklist, it will be impor-
of free cells in the peritoneal cavity tant to collect data on other points of Tracts of Domestic
of T3 colon cancers was high and ex-
pected to have a worse outcome.
contention that include, but are not Animals: Sentinel Event?
limited to, the number of peritumoral